question about cutting sheet metal..

[Venesectrix]

I'm trying to make some metal chest armor. I've got my templates(thanks to this forum) and a bunch of sheet metal from an old air conditioner.
It's about a millimeter thick..

I was wondering what are some ways to cut the metal.
I tried using a hacksaw, but it looks like that would take really long time.
On one thread I heard to use a jigsaw, but I don't think you can get much precision with that
I've got a dremel, but I wouldn't know what kind of tip to use..

peace,

Venesectrix

 

[BobaN00b]

bandsaw. that's what i own and will be using once I jump in and do the armor.

 

[TeamFett]

Foot powered shear or some hand shears is what I would use. Although the hand shears might leave some jagged edges and you can't really buy a foot powered shear. I've never used a bandsaw on sheet metal before, you could give that a try.

 

[BobaN00b]

I have a Rigid Upright Bandsaw.

- stock photo of my model.

You have to buy the metal cutting blades for it, but it cuts through like butter. Wear eye protection and gloves though.

 

[Blaxmyth]

I'm trying to make some metal chest armor. I've got my templates(thanks to this forum) and a bunch of sheet metal from an old air conditioner.
It's about a millimeter thick..

I was wondering what are some ways to cut the metal.
I tried using a hacksaw, but it looks like that would take really long time.
On one thread I heard to use a jigsaw, but I don't think you can get much precision with that
I've got a dremel, but I wouldn't know what kind of tip to use..

peace,

Venesectrix

Assuming that the metal is mild steel and is about 1 to 1.5 mm thick, it should be fairly easy to cut with a hacksaw or hand-operated nibbler. You could even try heavy tin snips. You can also get hacksaw blades for an ordinary jigsaw.

A trick I have found for using a hacksaw on sheet metal is to clamp the metal between two piece of plywood or MDF, then use the hacksaw at a very low angle, using the lower piece of wood as a cutting line. This stops the sheet metal from vibrating, which stops the teeth from digging in and doing their job as chisels, plus it means that each tooth takes a longer cut as it passes across the surface, say 2 or 3 mm instead of just 1 per stroke.

It has been ages since I used a jigsaw, but it worked OK, although it was harder to get the metal clamped in such a way that it didn't vibrate. Basically, more vibration = less cutting + much more noise.

You can get good results with hand held nibblers, but they are not too easy to come by. I'm not sure how expensive electric nibblers are where you are, but they would work very well. I use a Monodex hand nibbler, which will cope with mild steel up to about 1mm. It's fairly easy to use, but you'll develop a grip like a money lender's dog!

Attached is a photo of the hacksaw set up I use, showing some thin stainless being cut. BTW - don't ever try to cut stainless with anything other than a cutting wheel or a hacksaw - for some reason shears just slip and it even distorts or damages the blades.

It might be worth getting in touch with a local auto bodyshop - they do this sort of stuff for a living and know all the tricks.

Regards, Phil

 

[Venesectrix]

Hey thanks everyone!
Well, I do have a band saw table on my dad's Shop Smith, but I think it's meant for cutting wood. Blaxmyth, I think your mothod might work well, but if I'm using an hacksaw how do you cut the parts of the armor that curve? Rough cut it, then go back and file it down?

 

[BobaN00b]

Hey thanks everyone!
Well, I do have a band saw table on my dad's Shop Smith, but I think it's meant for cutting wood. Blaxmyth, I think your mothod might work well, but if I'm using an hacksaw how do you cut the parts of the armor that curve? Rough cut it, then go back and file it down?

Go get a metal cutting blade.

 

[Venesectrix]

Thanks BobaN00b. Yeah, I may try that at some point.

 

[bneally]

Since the metal is not that thick, I used a dremmel tool and a cutting disc. You could also use a die grinder if you access to an air compressor. This method is somewhat more difficult than a bandsaw, but a dremmel is less expensive. Just wear eye protection, as mentioned earlier, as the cutting disks may break. I used this method to put a piece of sheet metal on the back of my jet pack for added strength instead of plastic.

 

[Blaxmyth]

Hey thanks everyone!
Well, I do have a band saw table on my dad's Shop Smith, but I think it's meant for cutting wood. Blaxmyth, I think your mothod might work well, but if I'm using an hacksaw how do you cut the parts of the armor that curve? Rough cut it, then go back and file it down?

Yeah, forgot to mention that. For the outer curves, repeated cutting and filing is what I use, but I also have an old roller shear that I lucked on years ago. But it won't cut inside curves very well - that's when I use the nibbler. For small bits I use the dremel with a thin cutting blade, making a series of small pierce cuts, then finishing them with a file. When you file the edges, it really pays to have the edges supported between clamped ply or MDF, so you can run the file along the edge more, rather than straight across it. You can get round files as well - they are a great help on inside curves.

 

[BobaN00b]

MDF rules

 

[Venesectrix]

Hey would this work for the curved areas? http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=64-2960

 

[Blaxmyth]

Hey would this work for the curved areas? http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=64-2960

Yep, it'd probably work OK, although the throat might not open enough for thicker sheet. You should be able to get cheap sets of metal shears - left, right and straight cuts - for about $15 at most hardware stores. The left-right thing is that one cuts an inside curve one way, the other cuts the same curve from the opposite direction. Well worth checking out, plus getting out there and just experimenting. Have fun!

 

[Venesectrix]

So do you think I should just buy the shears instead of the nibbler?

 

[Blaxmyth]

So do you think I should just buy the shears instead of the nibbler?

Watch a couple of episodes of "Home Improvement", then decide!

If I had to choose one or the other, it'd be the shears, develop my skills with them, because they were the only option before nibblers, then move to nibblers later.

But really - you gotta get both!

 

[Venesectrix]

Thanks man I'll see what I can do